Caracul-like 7, a dominant mutation resembling

Krt2-6gCa (caracul).

Richard M. Samples, Patricia F. Ward-Bailey, Leah Rae Donahue, Roderick T. Bronson, and Muriel T. Davisson

Source of Support: The research was supported by NIH/NCRR grant RR01183 to the Mouse Mutant Resource (M.T.Davisson, PI) and Cancer Center Core Grant CA34196.

Mutation (allele) symbol: Cal7

Mutation (allele) name: Caracul-like 7

Gene symbol: Krt2-6g

Strain of origin: C.129s2(B6).I14tm1Gru

Current strain name: STOCK I14tm1Gru -Cal7

Stock #: 005409 (Available as DNA only from the Jackson Laboratory DNA Resource)

 

Phenotype categories: hair

Abstract

A spontaneous, dominant curly coat mutation resembling caracul (Krt2-6gCa) has been discovered and named caracul-like 7 (Cal7). This mutation maps to Chromosome 15 in the same region as Krt2-6gCa. The phenotype and  map position of Cal7 suggest that it may be a remutation to Krt2-6gCa however a direct test for allelism was not performed because caracul is only available as frozen embryos.

 

Origin and Description

This  dominant mutation was discovered in a breeding colony of C.129s2(B6).I14tm1Gru at The Jackson Laboratory in March of 2002 by Sean Sullivan. Mice homozygous or heterozygous for the Cal7 mutation are phenotypically the same in appearance and both are fertile. Mice carrying the Cal7 mutation are recognized at 3 weeks of age by their very curly coats and kinked vibrissae. With age, the coat of mutant mice straightens some and has a ruffled look. The original caracul mutation has a very similar dominant phenotype showing wavy hair and curved vibrissae.(MGD 2005)

Genetic Analysis

To determine the mode of inheritance an affected (Cal7/+) male was mated to an unrelated normal BALB/cByJ female. In 3 litters produced, 11 progeny were affected and 4 were normal, thus proving the mutation to be dominant.

Using our standard mapping procedures Cal7 was determined to map between D15Mit44 and D15Mit35 in 21 animals typed. The Ensembl placement of these markers and Krt2-6gCa is D15Mit44 at 101.0 Mb, D15Mit35 at 104 Mb, and Krt2-6gCa at 103.9 Mb. Consequently it is likely that Cal7 is a remutation to Krt2-6gCa.       

Pathology

Fur samples and pelt pads were prepared from a 3 week old mutant and a control littermate and were viewed microscopically. (See photos and description.) 

Acknowledgements

The authors wish to thank Sean Sullivan for the discovery of the mutant and Coleen Marden for her excellent technical assistance.

 

References

Mouse Genome Database (MGD) Mouse Genome Informatics Project, The Jackson Laboratory, Bar Harbor, Maine. World Wide Web

(URL:http://www.informatics.jax.org)

MGSC27.33c.1. Mouse Genome Sequencing Consortium

(URL: http://www.ensembl.org/Mus_musculus/)